Aqueous Biphasic Hydroformylation of Higher Olefins Catalyzed by Rhodium Complexes with Amphiphilic Ligands of Sulfonated Triphenylphosphine Analog

The catalytic performances of rhodium complexes with three new amphiphilic phosphine ligands, bis-(3-sodium sulfonatophenyl)-(4-tert-butylphenyl)-phosphine (3), phenyl-(3-sodium sulfonatophenyl)-(4-tert-butyl-phenyl)-phosphine (4) and bis-(4-tert-butylphenyl)-(3-sodium sulfonatophenyl) phosphine (5), in hydroformylation of 1-hexene, 1-octene and 1-dodecene have been studied. The steric attributes of free ligands are investigated by Tolman's cone angle method through geometric optimizations. The results reveal that the new phosphines are surface-active as the typical surfactants and the corresponding rhodium complexes show significant enhancements in the reaction rate and higher selectivities toward the normal aldehydes in comparison with those obtained by triphenylphosphine trisulfonate (TPPTS)- and triphenylphosphine disulfonate (TPPDS) rhodium complexes under identical conditions.     

水溶性铑-膦络合物催化烯烃氢甲酰化反应--阳离子表面活性剂的加速作用

介绍了以水溶性铑-膦络合物RhCl(CO)(TPPTS)₂作为催化剂前体在水/有机两相体系中催化烯烃氢甲酰化反应研究的进展,阐述了阳离子表面活性剂的加速作用和介稳态胶束-离子对协同作用机理关系.通过两相体系中界面分子组装和选择与烯烃分子链长相匹配的表面活性剂, 设计制备了高区域选择性复合催化剂体系.当采用双长链表面活性剂与铑-膦络合物组成的复合催化体系时,在不搅拌的情况下就显示出极高的催化活性.     

High Active and Regioselective Hydroformylation of 1-Dodecene Catalyzed by Rh-BISBIS in a Two-Phase System

The hydroformylation of 1-dodecene under aqueous/organic two-phase reaction conditions with rhodium catalysts derived from BISBIS (sodium salt of sulfonated 2,2′-bis (diphenylphosphinomethyl)-1,1′-biphenyl) in the presence of cationic surfactants was studied; regioselectivities appear to be sensitive to pressure. In all cases, the activities and regioselectivities for linear aldehyde were higher.     

High-pressure phase equilibrium for the hydroformylation of 1-octene to nonanal in compressed CO2

The hydroformylation reaction in supercritical carbon dioxide or CO₂-expanded liquids (CXLs) has many advantageous properties. However, accurate phase behavior and equilibrium must be known to properly understand and engineer these systems. In this investigation, the vapor-liquid equilibrium and mixture critical points of CO₂ systems with 1-octene, nonanal, 1-octene and nonanal mixtures, and mixtures of 1-octene, nonanal and syngas (CO/H₂) were measured at 60 °C up to 120 bar of pressure. The Peng-Robinson equation of state with van der Waals two-parameter mixing rule was employed successfully to correlate the binary mixture data and predict the ternary mixture data. The presence of CO/H₂ pressure increased the mixture critical points and decreased the volume expansion at any given pressure. In an actual reaction, the mixture critical point would increase throughout the reaction, while the volume of the liquid phase would decrease. These data will aid the understanding and reaction engineering for the hydroformylation reaction in CO₂-expanded liquids and supercritical fluids.     

反应工程因素对十二碳烯氢甲酰化反应速率和正异比的影响

在研究烯烃氢甲酰化反应过程中 ,水溶性催化剂由于具有安全、易回收以及对环境友好等优点而受到广泛的关注[1] .水溶性铑膦络合物催化剂已成功用于丙烯氢甲酰化的工业生产 ,但 1-十二碳烯等长链烯烃的强烈憎水性使得氢甲酰化反应速率极低 .加入阳离子表面活性剂[2 ] ,在反应体系中形成胶束 ,可以提高 1-十二碳烯氢甲酰化反应速率 .水溶性铑膦络合物催化十二碳烯氢甲酰化反应是一个典型的气液液三相反应 ,影响宏观反应动力学和产物正异比的因素很多 .以前的实验已系统地研究了温度、压力、氢气与一氧化碳摩尔比、催化剂浓度、油水比、膦铑比…     

Rhodium catalyzed hydroformylation of 1-octene in microemulsion: comparison with various catalytic systems

In this work, we describe how addition of alkylpolyglycol ether type nonionic surfactant affects the hydroformylation of 1-octene in the presence of phosphine modified rhodium catalyst. Influence of different process parameters such as ligand excess and amount of surfactant on the reaction rate and selectivity were discussed. Direct comparison of microemulsion systems with classic processes was achieved by performing the reactions under comparable homogeneous and biphasic conditions. Thus, the experiments were carried out using catalysts such as unmodified rhodium carbonyl HRh(CO)₄ and HRh(CO)(PPh₃)₃ in homogeneous system, Rh–TPPTS complex in two-phase system and in association with co-solvent.     

水溶性铑络合物催化1-十二碳烯氢甲酰化反应器构型的初步探索

Hydroformylation of 1-dodecene was studied in a biphasic system using water-soluble rhodium complex [RhCl(CO)(TPPTS)2] as catalyst in the presence of cetyl trimethyl ammonium bromide as surfactant to enhance the reaction rate. Efforts were devoted to improve the performance of hydroformylation by exploring reactor the reaction configuration which enhanced the mixing, dispersion and interphase mass transfer. Experiments were carried out in a 0.5L autoclave at the total pressure of 1.1MPa and temperature from 363K to 373K. Several surface aeration configurations were tested, and higher hydroformylation rate with higher normal/branched aldehyde ratio produced were achieved. The experience suggest that improved reactor configuration by taking reaction engineering, measures is beneficial to better process economy in alkene hydroformylation.     

双环戊二烯在水溶性铑膦络合催化体系中的氢甲酰化反应

研究了采用水溶性铑膦络合催化体系对双环戊二烯的氢甲酰化反应，考查了反应温度、相转移剂ＣＴＡＢ、铑催化剂浓度等对反应的影响。氢甲酰化反应的产物经ＧＣ／ＭＳ鉴定是不饱和的三环癸单醛     

高碳烯烃氢甲酰化研究进展

水/有机两相催化体系被成功应用于低碳烯烃氢甲酰化反应.对于水溶性差的高碳烯烃,其氢甲酰化反应速度远远低于低碳烯烃.本文论述了近年来铑催化高碳烯烃氢甲酰化反应的研究和开发进展,其新型配体和新催化体系的研究开发一直是该领域的研究热点.主要涉及两相反应体系中的水溶性膦配体以及均相催化剂固相化、氟两相催化、非离子液体催化体系和超临界CO2中的氢甲酰化反应等几种新型反应体系.     

Vapor-phase surface modification of submicron particles

Submicron iron oxide red, TiO₂ and talc particles were chemically modified twice in the same double-cone reactor with vapor of 2,4,6,8-tetramethylcyclotetrasiloxane(TMCTS) and then 1-dodecene, 1-tetradecene or vinyl terminated poly(dimethylsiloxane). For the second modification alumina balls coated with hexachloroplatinic(IV) acid by simple impregnation of the catalyst-containing solution were used as a catalyst, reducing aggregation of the particles as well. The conversion of the second modification was even higher than that obtained in conventional liquid-phase hydrosilylation under comparable process conditions. Segregation of the particles from the ball was important for large volume modification. Under the given particle loading, the optimal ball size and catalyst concentration existed for the efficient use of catalyst. The ball catalysts were effective in four consecutive batches without any appreciable decrease in the conversion. Intermittent tumbling and the use of baffle enhanced the conversion of any gas-solid reaction such as both the first and the second modifications, minimizing simple tumbling (no mixing) and lump formation of particles.     

Polyether triaryl phosphine oxides for hydroformylation of oleyl alcohol in micellar catalysis

Water-soluble triaryl phosphine oxides bearing polyether moiety proved to be efficient ligand for rhodium catalyzed aqueous/organic two-phase hydroformylation of water-immiscible oleyl alcohol. Under the selected conditions, yield of aldehydes reached 83.3% with 70 h⁻¹ of TOF. The in situ formed catalyst was easily separated from the reaction mixture and could be employed in the successive reaction runs. It was observed that the catalyst exhibited high activity in the isomerization of oleyl alcohol during the hydroformylation. As a result, 19% of hydroformylation product was determined to be 18-formyl-octaldecyl-1-ol.     

Amphiphilic phosphines for catalysis in the aqueous phase

Two new phosphines, Tris[p-(10-phenyldecyl)phenyl]phosphine and 2,2′-Bis{di[p-(10-phenyldecyl)phenylphosphinomethyl}-1,1′-biphenyl were successfully synthesized and sulfonated in concentrated H₂SO₄. The resulting water soluble surface active phosphines were applied to the rhodium catalyzed hydroformylation of higher olefins. It is found that these two ligands are not only excellent for octene hydroformylation, but catalyze tetradecene hydroformylation under two phase conditions as well. Rates and selectivities are superior to TPPTS modified rhodium catalysts under the same reaction conditions.     

An exploratory study of the addition reactions of ethyleneglycol, 2-chloroethanol and 1,3-dichloro-2-propanol to 1-dodecene

sec-Dodecyl ethers of ethyleneglycol, 2-chloroethanol, and 1,3-dichloro-2-propanol have been prepared by reacting 1-dodecene with the corresponding substituted alcohol in the presence of BF₃ as a catalyst. The addition of ethyleneglycol to 1-dodecene proceeds best in the presence of a reaction solvent (e.g., nitromethane), which suppresses side reactions. The resulting ethers consist almost exclusively of the mono-sec-dodecyl derivatives. The maximum yield was about 50 mol% on dodecene intake and 75%m on converted ethyleneglycol. The addition of 2-chloroethanol and 1,3-dichloro-2-propanol to dodecene can easily be conducted without a reaction solvent; yields are 77 and 67 mol% respectively on 1-dodecene intake. A reaction scheme for the addition of ethyleneglycol to 1-dodecene is proposed.     

Water-soluble rhodium/phosphonate–phosphine catalysts for hydroformylation

We have developed new and efficient routes to modify phosphines with phosphonic acid groups. Phosphonate–phosphines showed high solubilities in water and were used to immobilise rhodium catalysts in the aqueous phase of biphasic systems. In the two-phase hydroformylation of propylene, some of the novel catalysts showed activities and regioselectivities similar to those of Rh/TPPTS. Amphiphilic Rh/phosphonate–phosphine catalysts were found widely superior to Rh/TPPTS in the hydroformylation of 1-octene.     

Hydroformylation of C8 olefins catalyzed by rhodium–inorganic ammonium salt systems

The effect of inorganic ammonium salts which contain group VIB metals of the periodic table (ammonium chromate, ammonium dichromate, ammonium molybdate and ammonium tungstate) as additives on the catalytic performance of Rh catalysts for the hydroformylation of C₈-olefins and 1-dodecylene has been investigated. Modification of rhodium with ammonium salts could increase the yield of aldehydes in the hydroformylation of the olefins without phosphine oxide or phosphine ligands and also decrease Rh loss in the distillation process for the separation of the products from the catalyst.     

Ammonium Salts with Polyether-Tail: New Ionic Liquids for Rhodium Catalyzed Two-Phase Hydroformylation of 1-Tetradecene

By attaching the polyether chains to ammonium salts, a novel class of ionic liquid termed polyether melt is prepared. Such polyether melt contains no fluoride and hence is environmentally more benign. Applying this polyether melt as a polar phase, the hydroformylation of 1-tetradecene catalyzed by Rh complex catalyst in two-phase medium was investigated. The rhodium catalyst immobilized in this polyether melt is readily separated from the aldehyde product phase by decantation and has been reused for seven times without obvious loss of activity.     

Biphasic and Flow Systems Involving Water or Supercritical Fluids

Two processes are described for improving reaction rates for relatively hydrophobic substrates in aqueous biphasic systems. In the first, 1-octyl-3-methylimidazolium bromide ([Octmim]Br) increases the rate of hydroformylation of 1-octene from 8% conversion in 24 h to full conversion of 1.5 h. Phase separation is fast and catalyst retention is good. 1-Hexyl-3-methylimidazolium bromide gives little rate enhancement, whilst 1-decyl-3-methylimidazolium bromide gives stable emulsions., The mechanism of action of these additives is discussed. In the second approach, functionalising PPh₃ with amidine groups allows the rhodium catalysed hydroformylation of 1-octene in toluene with a very high reaction rate. The catalyst can be switched between toluene and water by bubbling CO₂ and back into toluene by bubbling N₂ at 60 °C. This switching has been used to separate the catalyst from hydrophobic (from 1-octene) or hydrophilic (from allyl alcohol) aldehydes obtained from hydroformylation reactions. CO₂ expanded liquids have been shown to be effective media for transporting substrates and catalysts over supported ionic liquid phase (SILP) catalysts. The advantages offered over all gas phase and liquid phase catalysts are discussed.     

均相铑膦催化体系下1-癸烯氢甲酰化反应研究

氢甲酰化反应是目前生产醛醇化合物最重要的反应之一,高碳烯烃氢甲酰化工艺改进是研究的难点和热点之一。探索了一种C10烯烃氢甲酰化反应的工艺,以三苯基膦（Ph₃P）和亚磷酸三（2-叔丁基-4-甲氧基苯基）酯（L_A）混合物为配体,与乙酰丙酮二羰基铑原位合成的催化体系催化1-癸烯氢甲酰化反应。系统考察了反应温度、反应压力、铑浓度、膦铑比、无机盐添加剂对反应的影响。结果表明,在n（Ph₃P）/n（L_A）=10、铑质量分数为280 mg/kg,1-癸烯用量（相对于甲苯）为0.3 g/mL,n（膦）/n（铑）=45、反应温度为90 ℃、反应压力为2.0 MPa、n（一氧化碳）/n（氢气）=1条件下反应4 h,1-癸烯转化率为98.1%、醛收率为93.2%、正异比为7.5。研究还发现,在减压蒸馏产物与催化剂分离时,加入无机盐添加剂能够提高催化剂的稳定性,减少铑损失。     

A Comparative Study of the 1-Hexene Hydroformylation Either Under Syngas Conditions or with Paraformaldehyde Catalyzed by Rhodium/Diphosphine Systems

In order to carry out a comparison, the hydroformylation of 1-hexene to their corresponding aldehydes (heptanal and 2-methyl-hexanal) was studied both under syngas conditions and with paraformaldehyde using the catalytic rhodium/diphosphine precatalysts; the catalytic systems were formed in situ by the addition of one or two equivalents of the corresponding diphosphine, Ph₂P(CH₂)_nPPh_2, n = 2 (dppe), 3 (dppp) and 4 (dppb), to the carbonyl complex Rh(acac)(CO)₂. For the hydroformylation reactions under syngas conditions, the more active systems were the ones containing one equivalent of the diphosphine, which produce trigonal bipyramidal species like RhH(CO)₂(diphos). The activity and selectivity of these systems strongly depend on the bite angle of the ligand: when the bite angle increases both parameters are higher (dppb > dppp > dppe). Contrary to these results, for the reaction with paraformaldehyde, the systems containing two equivalents of the diphosphine ligand, which produce the cationic square planar species [Rh (diphos)₂]⁺, were more active than those containing one equivalent; the reaction rate decreases with the enlargement of the carbon chain of the bridge between the two phosphorous atoms of the diphosphine (dppe > dppp > dppb). These results may be explained by a higher steric effect on the metal center, which probably produces a decreasing of the rate of the CH₂O oxidative addition reactions. For both reactions, these effects were explained through DFT calculations of the corresponding resting states.     

Unraveling the Bite Angle Effect: New Ligands for Selective Hydroformylation of Internal Alkenes

Rhodium catalyzed hydroformylation is one of the most important applications of homogeneous catalysis in industry[1]. The addition of CO and H₂ to alkenes is a mild and clean method for the functionalization of hydrocarbons. The atom economy of the reaction can be 100% and the selectivity for the desired aldehyde can be very high. Most of the six million tons of aldehydes produced annually by this process is converted into plasticizers for polymers and detergent alcohols. Since the linear aldehydes are the desired products for these applications, a key issue in industrial hydroformylation is the control of regioselectivity. The generally accepted hydroformylation mechanism is shown in Scheme 1. The active catalyst is the five-coordinated complex A, which usually contains two phosphorus ligands. This catalyst consists of two isomeric structures in which the phosphine ligands coordinate in a diequatorial (e-e) and in an equatorial-apical (e-a) fashion. Bidentate ligands can give rise to either of these two complexes depending on their natural bite angle.